This invention relates to vulcanizable polymer mixtures comprising of substantially saturated hydrocarbon elastomers and substantially saturated nitrile group-containing elastomers and to the co-vulcanizates produced therefrom by peroxide cross-linking.
Substantially saturated hydrocarbon elastomers include, for example, ehtylene/propylene or ethylene/propylene/diene copolymers (EPM or EPDM), as well as butyl rubber and polyoctenamer. They have a maximum of one double bond for eight carbon atoms. EPM and, in particular, EPDM are preferred.
EPM and EPDM are high-quality rubbers which are resistant to heat, chemicals, steam and hot water. They are obtained by copolymerisation of ethylene, propylene and optionally a non-conjugated diene and may be cross-linked by means of peroxides, and also by means of sulphur in the case EPDM.
EPM and EPDM are described, for example, in "Rubber Chemistry and Technology", 45 (1972), 709-881.
Substantially saturated nitrile group-containing elastomers are obtained, for example by hydrogenation of nitrile rubbers (butadiene/acrylonitrile copolymers). Vulcanizates thereof are distinguished by high strength.
Such elastomers are known, for example from U.S. Pat. No. 3,700,637 and German Offenlegungsschrift No. 25 39 132.